[PATCH 03/16] dt-bindings: timer: arm,arch_timer: Fix requirements for interrupt description

[Marc Zyngier <maz@kernel.org>]

The arm,arch_timer DT binding is extremely imprecise in describing
the requirements for interrupts.

Follow the architecture by making it explicit that:
- the EL1 secure timer irq is required if EL3 is implemented
- the EL1 physical timer irq is always required
- the EL1 virtual timer irq is always required
- the EL2 physical timer irq is required if EL2 is implemented
- the EL2 virtual timer irq is required if FEAT_VHE is implemented

The consequence of the above is that the minimum number of interrupts
to be described is 2, and not 1.

Finally, clean up the description which made the assumption that
the timers are plugged into a GIC (unfortunately, that's not always
true), drop the MMIO nonsense that has long be moved to a separate
binding, and use the architectural terminology to describe the various
interrupts.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 .../bindings/timer/arm,arch_timer.yaml        | 21 +++++++------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/Documentation/devicetree/bindings/timer/arm,arch_timer.yaml b/Documentation/devicetree/bindings/timer/arm,arch_timer.yaml
index c5fc3b6c8bd0b..c65e48a155ab6 100644
--- a/Documentation/devicetree/bindings/timer/arm,arch_timer.yaml
+++ b/Documentation/devicetree/bindings/timer/arm,arch_timer.yaml
@@ -10,13 +10,8 @@ maintainers:
   - Marc Zyngier <marc.zyngier@arm.com>
   - Mark Rutland <mark.rutland@arm.com>
 description: |+
-  ARM cores may have a per-core architected timer, which provides per-cpu timers,
-  or a memory mapped architected timer, which provides up to 8 frames with a
-  physical and optional virtual timer per frame.
-
-  The per-core architected timer is attached to a GIC to deliver its
-  per-processor interrupts via PPIs. The memory mapped timer is attached to a GIC
-  to deliver its interrupts via SPIs.
+  The per-core architected timer is expected to deliver per-CPU interrupts
+  (commonly to a GIC to deliver its per-processor interrupts as PPIs).
 
 properties:
   compatible:
@@ -33,13 +28,13 @@ properties:
           - const: arm,armv7-timer
 
   interrupts:
-    minItems: 1
+    minItems: 2
     items:
-      - description: secure timer irq
-      - description: non-secure timer irq
-      - description: virtual timer irq
-      - description: hypervisor timer irq
-      - description: hypervisor virtual timer irq
+      - description: EL1 secure physical timer irq, if EL3 is implemented
+      - description: EL1 non-secure physical timer irq
+      - description: EL1 virtual timer irq
+      - description: EL2 physical timer irq, if EL2 is implemented
+      - description: EL2 virtual timer irq, if FEAT_VHE is implemented
 
   interrupt-names:
     oneOf:
-- 
2.47.3